Basic physics question

I am just wondering what is exactly expected when asked "express the answer in terms of g, (acceleration due to earth's gravity). I am thinking it means divide the result by 9.8N? What is the resulting unit?

But my question is asking to calculate centripetal acceleration (Ac = 4PI^2rf^2) and to express that in terms of g. How would that make sense?

It makes sense because it allows us to compare other accelerations to the familiar experience of weight. Pilots in high performance jets experience very high centripetal forces in tight turns. It is common to express these forces as "g-forces", and they can run up to 7 to 8 times their weight. They wear special suits to keep the blood from draining out of their heads, and still black out if they stay in such a turn for long. A force of n "Gees" corresponds to an acceleration of a = n*g.